Triggering DAQmx from a GPIB device

Question

Hi,
We have a GPIB device that sends out trigger signal to the computer, and we want the DAQmx card (PCI-6052E) to listen to that trigger signal. We tried doing this:
m_referenceTriggerEdge = DAQmxAnalogEdgeStartTriggerSlopeRising;
    try
        // Create the voltage channel
        m_task->AIChannels.CreateVoltageChannel(channelName, "",
            static_cast<DAQmxAITerminalConfiguration>(-1),
            minimum, maximum, DAQmxAIVoltageUnitsVolts);
        // configure the internal clock
        m_task->Timing.ConfigureSampleClock("", rate, DAQmxSampleClockActiveEdgeRising,
            DAQmxSampleQuantityModeFiniteSamples, samplesPerChannel);
        // Set up the start trigger
        m_task->Triggers.StartTrigger.ConfigureAnalogEdgeTrigger(triggerSource,
            m_referenceTriggerEdge, triggerLevel);
        m_task->Triggers.StartTrigger.AnalogEdge.Hysteresis = hysteresis;
        (omitted a few graphing codes in between)
        // Begin the reading or whatever
        m_reader = std::auto_ptr<CNiDAQmxAnalogMultiChannelReader>
            (new CNiDAQmxAnalogMultiChannelReader(m_task->Stream));
        m_reader->InstallEventHandler(*this, OnEvent);
        m_reader->ReadMultiSampleAsync(samplesPerChannel, m_data);
By default, triggersource is set to "PFI0" and triggerlevel is set to "1.00". The result, however, is rather peculiar: There will always be a 200284 error, unless the triggerlevel is set to "0" while its previous run is set to "1". In other words, if first run the acquisition using triggerlevel "1", which would still give the error, but then if the next one is set to "0", DAQ sees the trigger. However, if one continues to run using triggerlevel "0", the subsequent runs will give the error. Where did we do wrong?
Also, is there a way to use Measurement and Automation to measure the trigger signal coming cross GPIB?
Thanks,
Jim

Answer 1

Hi Jacob,
Thanks for the reply! The error message is as followed:
Some or all of the samples requested have not yet been acquired.
To wait for the samples to become available use a longer read timeout or read later in your program. To make the samples available sooner, increase the sample rate. If your task uses a start trigger,  make sure that your start trigger is configured correctly. It is also possible that you configured the task for external timing, and no clock was supplied. If this is the case, supply an external clock.
Property: CNiDAQmxStream::ReadRelativeTo
Corresponding Value: DAQmxReadRelativeToCurrentReadPosition
Property: CNiDAQmxStream::ReadOffset
Corresponding Value:
Task Name: aiTask
Status Code: -200284
And the rest of the default parameters are below:
minimum = 0.000
maximum = 10.000
samplesPerChannel = 1000
rate = 1000
hysteresis = 0.00
Thanks,
Jim